Magma oceans as a critical stage in the tectonic development of rocky planets

TL;DR

This paper reviews the role of magma oceans in planetary development, examining their effects on mantle structure, crust formation, and tectonic activity, with new calculations on mantle oxidation states and implications for tectonics.

Contribution

It introduces new calculations of mantle oxidation during magma oceans and discusses their impact on mantle stability and tectonic evolution of rocky planets.

Findings

Magma oceans influence mantle stratification and crust formation.

Crystallization may cause mantle overturns affecting tectonics.

Recent models suggest mechanisms for earlier plate tectonics onset.

Abstract

Magma oceans are a common result of the high degree of heating that occurs during planet formation. It is thought that almost all of the large rocky bodies in the Solar System went through at least one magma ocean phase. In this paper, we review some of the ways in which magma ocean models for the Earth, Moon, and Mars match present day observations of mantle reservoirs, internal structure, and primordial crusts, and then we present new calculations for the oxidation state of the mantle produced during the magma ocean phase. The crystallization of magma oceans likely leads to a massive mantle overturn that may set up a stably stratified mantle. This may lead to significant delays or total prevention of plate tectonics on some planets. We review recent models that may help partly alleviate the mantle stability issue and lead to earlier onset of plate tectonics.